diff --git a/interpreter/src/vm/types.rs b/interpreter/src/vm/types.rs
index 19cf257..df210b4 100644
--- a/interpreter/src/vm/types.rs
+++ b/interpreter/src/vm/types.rs
@@ -376,6 +376,12 @@ impl<'a> AwkValue<'a> {
         }
         match self {
             // TODO: NaN and infinities.
+            // An integral value is written as an integer, as by "%d" (POSIX),
+            // so 2^64 and 1e16 keep all their digits and -0 is "0".
+            Self::Float(f) if f.0.is_finite() && f.0.fract() == 0.0 => {
+                let n = if f.0 == 0.0 { 0.0 } else { f.0 };
+                out.extend_from_slice(format!("{n:.0}").as_bytes());
+            }
             Self::Float(f) => {
                 let mut buf = zmij::Buffer::new();
                 let s = buf.format(f.0);
diff --git a/tests/by-util/test_awk.rs b/tests/by-util/test_awk.rs
index 9819842..10a115c 100644
--- a/tests/by-util/test_awk.rs
+++ b/tests/by-util/test_awk.rs
@@ -1005,3 +1005,18 @@ fn test_referencing_an_element_creates_it() {
         .succeeds()
         .stdout_only("1 1 2 0\n");
 }
+
+#[test]
+fn integral_numbers_print_as_integers() {
+    ucmd()
+        .arg("BEGIN { print 2^64, 1e16, -1e16, -0; x = 1e16 \"\"; print x }")
+        .succeeds()
+        .stdout_only(
+            "18446744073709551616 10000000000000000 -10000000000000000 0\n10000000000000000\n",
+        );
+    ucmd()
+        .arg("{ print $1 * 1 }")
+        .pipe_in("5e20\n")
+        .succeeds()
+        .stdout_only("500000000000000000000\n");
+}